Drawing and plotting device.



110.814,789. l PATENTED MAR. 13, 1906.

E. D. MAGKINTOSH.

DRAWING AND PLOTTING DEvICE. APPLIGATION FILED DB0.21,1904.

FIG. l. 6,

lll

: 11,' 2.2, 22 WITNESSES; FG INVENTOR:

support provided withv one is a section taken vupon plane of line 4 4 or table adapted to 'UNITED sfm'rEs2 ,PATENT .oEinoE EDWARD D. MAoKiN'iosH, oF NEW YORK, N. Y. DRAWING AND PLQTTING D EvllcE.- i

Application filed December 21,1904. Serial'No. 237,787.

To all whom it may concern.-

Be it known thatI, EDWARD D: MAoKIN- TosH, a citizen of the l-United States, residing in the city of New York, borough of Brooklyn, county of Kings, and State of New York, have invented certain new and useful Improvements in Drawing and Plotting Devices, of which the'following is a specification sufficient to enable others skilled in the art to which the invention appertains to make and use the same.

i asjherein set forth,'whereby a protractor and connections are rendered readil adjustable longitudinally upon and with re ation to the laterally movable flat blade and whereby the saidprotractor and connections while normally .loose thereon may be quicklyv andi conveniently locked temporarilyin a desired orA prescribed manner essentially purposes. l

My invention also includes certain details in the construction andfarrangement of parts hereinafter described and claimed specifically. In the accompanying drawin s, Figure l is a plan representing more or ess diagrammatically the essentialfeatures of my invention. Fig.- 2 is a plan, upon an enlarged scale,- of the protractor, slide, and connec tions and .adjoining parts. Fig. 3 is an elevation of the parts shownin Fig. 2. Fig. 4

Fi 2. Y

'he character 1 represents a drawing board hold the paper or other material, upon the surface of which a plan or drawing is to be made. f l

2 is ak straightl atl blade or equivalent supporting cross-bar extendin 'transversely over theboard or table 1 am? connected to and controlled by mechanism by which it is always maintainedin-parallelism with a real vor imaginary base or .line 1), which for convemence of reference maybe herein desig- Specification of Letters Patent.

movable flat blade is at or near position upon said laterally-` movable flat blade in positive, for the time being, to all intents and.

Patented March 13, 190e.

nated the horizontal base. There aref various/well known. mechanical expedients which may be resorted to to preserve the alinement and parallelism of the supportingblade. or its equivalent irrespective of the `position of the same over and upon the draw- 1ng-surface, and I do not restrict myself in thls respect, the arrangement described herein being shown by way of illustration only,

*since the distinguishing'feature of my invention in this connection consists in the fact that whereas heretofore the protractor 111 has been pivotally supported upon a fixed center on the laterally-movable flat blade 2,A ,in the carrie y resent case such center or pivot 10 is for maintaining the parallelism of the.

In the arrangement shown the paral ellyits opposite extremities fastened to a exible band 3,

preferably formed ofvine piano-wire or the ke, as at 4 and 5, Fig. 1. rIhis band 3 passes around six guides 6, which I prefer to make in the form of loose pulleys turning on pins secured to the table or board 1. The pulleys 6 are so locatedon the board or table `1l in any suitable manner that the two strands 7 and 8 of the flexible band3 are parallel and upon aslide 9,'resting on the top of and .adjustable longitudinally upon the said 'parallelly-movable flat blade 2, the mechan- Iism Alatter being, obviously' of secondary import.

in the present case perpendicular. or vertical with relation to the base-'line b, althoughthis is not material provided the said strands 7 and 8 are parallel,y so that any longi-tudinal movement of one'strand is accompanied by a like and equal movement of the other strand,

causing the flat blade 2, fastened to the said,`

two strands, to move laterally to `the same extent at both ends.

The slide 9 is made'in'the form of a plate,

which normally rests loosely above the bottom of the flat blade 2v and is fitted thereto in s uch manner as to be'capable of movement independently lengthwise of the same whilemaintainin a rescribed relation thereto, the flat blade 2 shown in Fig. 1 ofthe draw- IOL') ings) being provided lwith downwardly-pro# jecting lips or shoulders@ a (shown in dotted lines) at either end, which limit its movement longitudinallyby reason of their proximity f i to the edges of the boarjd or table-1. This' limitation ofy the'longitudinalmovement of therblade 2 is desir'a le in the arrangement shown in the drawings,but is not essential 1n IOS lI if' `mechanism'for preserving the parallelism of made .forthe longitudinal as we 'movement of saidparallelly-movable blade 2.

the supporting-blade 2, in which rovision is It is to be noted in this connection that the under surface of the blade 2 rests directly upon the board 1. y l

A pivot 1'0 is iitted to turn in an eye 10a in the slide 9, said pivot being rigidly secured to the protractor 11 by any suitable or well-known means, as by the set-screw and washer shown in Figs. 2 and 4 of the drawings. The protractor 11 is rovided with one or more arms 12, preferab y two, extending radially from the ivotal center of the protractor and at rig t angles with relation to each other. The radial arm or arms 12 afford means of attachment for one or more rulers or straight-edges 13, on the edge or edges of which any suitable or desired scale or scales ma be represented. The concentric edge of t e protractor 11 may be beveled, as shown at 14 in the drawings, although this is not essential. Such concentric edge is, however, preferably formed with notches 15 for engagement with a pawl 16, pivotally connected tothe slide 9 and held against the concentric edge of the protractor 1 1 (or in any of the notches 15 therein) by a sprin 17. The latter is made strong enough an the ratchet and pawl are so formed and arranged that the parts are held only with sufficient force to prevent their accidentaldisplacement when moved about over the surface to be drawn upon, the resistance to be overcome being insufficient to interfere materially with the intentional shifting or adjustment of the protractorfrom one notch to another or to any intermediate position between notches with relation to the` pawl 16. The notches are' located on the concentric edge of the protractor 11 in such manner as to engage the pawl successively when the ruleror rulers 13 stand at certain frequently-required angles, more particularl zontal, and at t rty, forty-five and sixty .degrees from the latter. The ruler or rulers may be set toany other desired angle by settin the proper marks on the concentric scale sli of t e protractor to the index-line i on' a block 18 ,secured to the slide 9, adjoining said con@ centric edge of the protractor, as shown iny Figi. 2. Another block 19, also secured to the -e 9, adjoining the said concentric edge of the protractor 11may be clamped against I Aat any angle to which it is set.

l tersone of the notches 15.

'such concentric edge by, means of a screw-nut or equivalent 20 whenit is desired to secure the protractor positively, for the time being, This clamp 2O need ndt, however, be used ordinarily when such angle is one at which the pawl en- The slide 9 is formed with a lip or shoulder 21 to bear against thelong straight-edge of the parallelly-movable fiat blade 2, vand a ldog 22 is arranged to lbear against the oppoas lateral at the vertical and hori-- lever 24 rests upon the protractor 11 and when pen or pencil is to be used against one of the edges of a ruler or straight-edge 13 the said lever 24 is pressed down, so as to pinch the protractor between it and the slide 9, and thus tend to prevent the shifting or turning of the protractor on its pivot', but this pressure instead of beingapplied directly to the lever 24 is applied primarily to the arm 26 of a bell-crank lever 27, fulcrumed between the two ears 29 on the said'lever 24, the other arm 28 of the bell-crank lever 27 engaging a slot or recess 28a (see Fig. 4) in the bolt 23 before named, so that the pressure on the arm 26 which effects the clampin of the protractor 11 to the slide 9, also acts t rough the bolt 23 to draw the dog 22, attached thereto, into contact With the blade 2, thereby pinching formed for its reception in the dog 22.

against the edges of the said rulers, the protractor being vset to give them the desired angle to the horizontal` or vertical and pressure being applied'to the arm 26 toy simultaneously clamp the protractor 11 to its slide 9 and the latter to the blade 2 and to hold the blade 2 in position upon the drawing board or table, all this being accomplished with sufiicient force to prevent any ofthe parts from shifting when a pen or pencil is brought to bear against an edge of a ruler, but with an expenditure of strength on the part of the user n o greater,if'as great, as that required to hold the blade of an ordinary T in osition during use. This feature of practica ly lock# ing the parts temporarily in a prescribed position for actual use by aslight and natural pressure upon the arm 26is an important and distinguishingv feature of my invention, the parts being so arranged that upon the removal of the pressure the slide may be freely movable support 2.

By moving the blade 2 laterally and the adjusted longitudinally upon thegparallelly-f.y

slide 9 lengthwise thereon it is obvious that the ruleror rulers 13 may be brought to any required position u on the surface to be drawn upon,.and in rawing lines the scale or IIO scales on the ruler or rulers may advantageously be used to determine their lengths.

Distinguishing features of my structure are that the flat bladel 2 rests on the drawingboard when it is available for'ruling long lines and that the slide 9 consists of a plate which simply rests above the bottom of the flat blade 2 and is normally loose thereon, being held against displacement on the blade 2 by the lip 21 at one edge of the blade and the dog 22 at the other edge thereof. Thus in the absence of pressure applied to force the` dog 22 against the opposed edge of the blade 2 the slide 9 has a slight lateral play upon the blade 2, such play being limited by the dog 22 and lip 21, but being suicient to admit of the quick and easy adjustment of the slide longitudinally in either direction upon the flat blade 2. The pinching of the edges. of the at blade 2 by and between the lip 21 and the dog 22, as set forth, is also a distinguishing and important feature, since the slide may be thereby instantaneously locked in a prescribed position upon the blade 2 and as quickly released. i

What I claim as my invention, and desire to secure by Letters Patent, is-

1. In a drawing and plotting instrument of the character designated the combination of a laterally-movable blade, means connected therewith for maintaining its parallelism With relation to a prescribed base-line, a slide movable longitudinally upon said laterallymovable blade, and a protractor pivotally attached -to said slide and formed with means for' the support of a ruler and a pressure-lever and bolt actuated thereby upon the slide, whereby a downward pressure may be exerted upon the protractor, slide and blade, to hold the parts in a prescribed position with relation to each other, the slide being simultav neously clamped to the blade for the purpose descrlbed.

2. In a drawing and plotting instrument of the character designated, the combination with a drawing-board of a laterally-movable blade, means connected therewith and with the board for maintaining its parallelism with relation to a prescribed base-line on the board, a slide movable longitudinally upon said laterally-movable blade, a protractor pivotally attached to said slide and formed with means for the support of a ruler, and a pressure lever and bolt actuated thereby upon the slide whereby a downward pressure 'may be exerted upon the protractor, slide,

blade and board to hold theparts in a prescribed position with relation to each other, the slide being simultaneously clamped to the blade for the purpose described.

3. In a drawing and plotting instrument of the character designated, the combination with a drawing-board of a laterally-movable blade, means connected therewith and with the board for maintaining its parallelism with relation to aprescribed base-line onthe board, a slide movable longitudinally upon s aid laterally-movable blade, a protractor `pivotally attached to said slide and formed with means for the support of a ruler, means for adjusting the protractor axially on the slide and holding it in a prescribed and a pressure-lever and bo by upon the slide, whereby a downward pressure may be exerted upon the protractor, slide, blade and board, to hold the partsin a prescribed position with relation to each other, the slide being simultaneously clamped to the blade for the purpose described.

4. In a drawing and plotting instrument, a laterally-movable blade, a slide movable longitudinally upon 'said' laterally movable blade, a ruler supported on said slide, and means whereby pressure acting temporarily in a direction toward and perpendicular to the flat side ofthe said blade will cause the said osition thereon,

`slide to be temporarily clamped edgewise upon and against said laterally-movable blade in the direction of the width of the latter for the purpose described.

5. In a drawing and plotting instrument a blade, a slide movable longitudinally thereon, and a pressure-lever and bolt so arranged that the movement of an arm of the pressurelever toward a flat side of theblade causes the latter to be pinched on two ed es between a lip on the slide and another on t e bolt.

EDWARD D. MAoKiNTosH.

Witnesses :I

D. W. GARDNER, GEO. WM. MIATT.

t actuated there-' 

